[pgrouting-users] pgRouting and multi-core

[Stephen Woodbridge]

On 7/23/2013 7:55 AM, Yaron Lev wrote:
> Hi,
>
> i was looking for some information about weather or not pgRouting is
> utilizing more than one core if available.
>
> from the limited testing i made, and from googling (i found very little
> refrences), i think pgRouting does not support multi-core processing as of
> now.
>
> i will appreciate if anyone can confirm it, or give any information about
> it.

PgRouting is built on top of Postgresql so to the extent that postgresql 
can use multiple cores to process multiple requests we do. I you are 
asking if the routing algorithm itself is run in threads or using 
something like parallel graph algorithms? the answer is no.

Also you should be aware the solving the graph is less then 50% of the 
cost of answering a query because we have to query the database for the 
edges, build the graph, solve the graph and return the results back to 
the client. selecting the edges and building the graph likely take 
2/3rds of the processing time for a given query. The edge selection is 
probably done in a separate core/thread/process by the database from 
that that the rest of the processing is taking place in.

-Steve